With a Wednesday deadline to file a request to the U.S. Supreme Court to hear an appeal in the case, Mayfield opted not to continue his quest to prove that NASCAR erred in determining that his May 1, 2009 drug test was positive for methamphetamines.

Mayfield, who has five career Cup wins and made the Chase twice, has been suspended by NASCAR since May of 2009 except for a brief period when he won a temporary injunction but never raced. He claimed that the test was a false positive caused by a mix of the prescription medication Adderall and the over-the-counter allergy medication Claritin D.

A U.S. District Court judge ruled in favor of NASCAR in January 2010 before the case ever went to trial. The U.S. Court of Appeals upheld that ruling in March.

The basis of the ruling was that Mayfield could not sue NASCAR because of waivers he signed regarding implementation of NASCAR’s substance-abuse policy. The waivers are part of the agreement a driver signs with NASCAR in order to participate.

“We’re probably going to move on,” Mayfield said in April. “They won on a technicality, a paper I had to sign to participate.”

NASCAR officials viewed the rulings as pivotal for them to be able to regulate the sport and administer its substance-abuse policy.

“We’re pleased that this case is behind us,” NASCAR spokesman David Higdon said. “The courts supported our position that NASCAR can establish reasonable rules and requirements to help us regulate our sport.”

NASCAR, which began random drug testing in 2009, issued a more detailed substance-abuse policy in 2010 that included a list of drugs considered illegal under the ban and an explanation of how the tests would be conducted and analyzed.

Mayfield will now focus on defending himself against criminal charges. He faces 19 felony charges in three North Carolina counties, primarily on stolen goods-related charges and one methamphetamine charge. Mayfield has said he is innocent of those charges. Out on bond, his upcoming court dates are Sept. 4, Sept. 10 and Sept. 17.